﻿// Copyright 2008 Chris Varley (http://www.contractdriven.net/)
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

namespace ContractDriven.CommonAssertions
{
	/// <summary>
	/// Describes a guarantee that an object reference is not null.
	/// </summary>
	public class NotNullAssertion : IAssertion
    {
        #region Memebers
        private readonly object _target;
        #endregion
        #region Constructor
        /// <summary>
		/// Describes a guarantee that an object reference is not null.
		/// </summary>
		/// <param name="target">the item to be checked for null</param>
		public NotNullAssertion(object target)
		{
			_target = target;
        }
        #endregion
        #region IAssertion Members

        public string FailureDescription
        {
            get { return Resource.NotNullAssertion; }
        }

        public bool Eval()
        {
            return _target != null;
        }

        #endregion
    }
}
